No Warm Air Coming Out Vents For Electric Heat Pump?

I have an electric heat pump/ac system. When I first turned it on this year, the outdoor fan wasn't working so I called a repair guy and he replaced the TXV and now it appears to be working normally. However, when the heat comes on, only cool air will come out of the vents but the house still warms up as normal. Does this have something to do with when it turns on the ac to defrost itself and then uses the heat strips to actually heat the house, or does this have anything to do with the freon? When, if ever, would I need to add more freon to the system? And also, when the house warms up and the heat pump turns off, it will start up again only about 15 minutes later ( with the temp being 35-45 F outside currently and the thermostat set to 68 F). Would new insulation help with this as well?

10 Answers

  • 1 decade ago
    Favorite Answer

    Hi , Lets begin with what you should be looking for is a difference in temperature between the air being supplied and the air returning to the unit. with a heat pump that should be between 10 to 12 degrees Farenheit. If the repair was done properly you won't be using the Emergency heat strips at this outside temp. they are very energy hungry. this will get expensive. the condition you are explaining sounds like there are a few problems still. first if freon (specifically 134a) leaks from a system you must locate the leak, recover the refrigerant, repair the leak, Vacuum the system down to 50 microns, then you recharge the system. if the vacuum isn't pulled down far enough you leave moisture in the pipe and will burn up the system. This is reason for a call back. ask the repair company to come by and check on it just for peace of mind. If they say they will charge you tell them you are going to call another service company to check on the unit. tell them to send a journeyman not an apprentice. and by the way your copper lines should be insulated.

    Source(s): thanks to my local union 393
  • 4 years ago

    Heat Pump Air Temperature

  • Anonymous
    5 years ago

    This Site Might Help You.


    No Warm Air Coming Out Vents For Electric Heat Pump?

    I have an electric heat pump/ac system. When I first turned it on this year, the outdoor fan wasn't working so I called a repair guy and he replaced the TXV and now it appears to be working normally. However, when the heat comes on, only cool air will come out of the vents but the house still...

    Source(s): warm air coming vents electric heat pump:
  • Anonymous
    1 decade ago

    The colder it gets outside, the less effective a heat pump is. In heat mode, it is basically being an air conditioner in reverse, extracting what heat it can from the outside air and transferring it to the indoors. The less heat available outside, the cooler the air coming out the vents inside. Heat pumps do best when it is above freezing and when the difference between the temperature outside and what the thermostat is set at is 10-15 degrees. Since you are trying for a 20+ degree difference, the heat pump is going to run a lot to make up that difference. If the air from the vents is noticeably warmer when it is warmer outside, then your system is probably working properly.

    Adding more insulation will help retain the heat once it is generated, so the system will be off longer between cycles.

    Source(s): Have a heat pump, too.
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  • 1 decade ago

    I'm a little confused by your question? You say you get cool air out of the registers, but the house heats up as normal? Perhaps what you are experiencing is the normal draft of the unit when it initially turns on before the warm air displaces the cool and heats up the home?

    With respect to the refrigerant in the AC, it has no bearing on the heat strips and is not a DIY project like filling the oil in your car. It does not need attention unless the unit develops leaks, then a professional HVAC mechanic should be consulted.

    As for the seemingly quick cycle of your heat pump, a number of factors could be contributing to this including your insulation values in the home, window types, solar orientation, door type, thermostat etc...You might ask your local power supply company if they offer energy audits?

    Source(s): 30 year custom home builder
  • 1 decade ago

    TXV valve has nothing to do with your condensing fan motor.

    The cool air is really room temp air. Your heat pump is prob not working correctly and your emergency heat is turning on (Heating Elements) . This is why your home is heating up normally. A TXV valve if i remember correctly was used last on 10 seers. I would suggest upgrading your heat pump to something more current and efficient (13+ Seer)

    Also at 35-45F ambient temp your heat pump should have no issues heating your home.

    Hope that helps. Best of luck

  • Anonymous
    5 years ago

    Your heat pump gets it's heat from the outdoor air. The compressor compresses and circulates refrigerant that has absorbed heat from the outdoor air. As it gets colder there is less heat to pick out of the air so axillary electric heat strips kick in to assist in the heating. It's typical that the heat pump would run a lot in colder temperatures but if you haven't had it serviced it should be done yearly on heat pumps to ensure it has the correct amount of refrigerant and things are working properly.

  • 1 decade ago

    The temperature of the air coming out of the vents should be at least 30 deg warmer than the air going into the filter. There is something wrong with the system. I do not recommend calling the same co. that fixed it before because a faulty TXV will not cause the fan to malfunction. Look for NATE Certified Technicians.

    Source(s): Texas HVAC Master, heat pump specialist
  • 1 decade ago

    That's a typical heat pump, it will not blow hot air or even warm air. its just warm enough to heat your house. but it sounds like its working. and yes if your vents are not insulated under the house they should be.

  • 1 decade ago

    a commom complaint with heat pumps is the supply air temperature coming from the regesters..a heat pumps heat output drops as outdoor temp drops...once outdoor temp drops below 40 degrees,its normal for the heat pump to run a lot,,even continuously,esp below 30 deg..... the auxillary electric heaters come on to assist the heat pump during these cold temps and during defrost....if the low voltage wires arent all connected as they should be then its possible you are getting cold air during defrost,,then the normal luke warm air the rest of the time.. a general guide for normal heat pump operation is that the supply air temp should be about 25 deg above room temp at 45deg outside,,,,then about 15-20 deg above room at 30 deg outside,,,then about 10 deg above room temp at 15 deg otside...temps need to be taken when tstat does not have auxillary heaters on,,just the heat pump....,.as long as it puts out these numbers,,and there is no excessive frost that builds up on the outdoor unit that doesnt clear itself every couple of hours,then the heat pump is working properly... the auxillary electric heaters should come on to assist the heat pump so that the room temp falls no more than 2 deg below your tstat setting,,the aux heaters should be on pretty often as temps fall below 20deg outside...sorry for all the info but there is a fine line between a properly working heat pump and a heat pump with a problem since they arent great heaters to start with...theyre meant for homes that dont have natural gas service and for whatever reason,didnt want oil or propane..........dan

    Source(s): in the biz
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